var CalendarData=new Array(100);
var madd=new Array(12);
var tgString="甲乙丙丁戊己庚辛壬癸";
var dzString="子丑寅卯辰巳午未申酉戌亥";
var numString="一二三四五六七八九十";
var monString="正二三四五六七八九十冬腊";
var weekString="日一二三四五六";
var sx="鼠牛虎兔龙蛇马羊猴鸡狗猪";
var cYear,cMonth,cDay,TheDate;
CalendarData = new Array(0xA4B,0x5164B,0x6A5,0x6D4,0x415B5,0x2B6,0x957,0x2092F,0x497,0x60C96,0xD4A,0xEA5,0x50DA9,0x5AD,0x2B6,0x3126E, 0x92E,0x7192D,0xC95,0xD4A,0x61B4A,0xB55,0x56A,0x4155B, 0x25D,0x92D,0x2192B,0xA95,0x71695,0x6CA,0xB55,0x50AB5,0x4DA,0xA5B,0x30A57,0x52B,0x8152A,0xE95,0x6AA,0x615AA,0xAB5,0x4B6,0x414AE,0xA57,0x526,0x31D26,0xD95,0x70B55,0x56A,0x96D,0x5095D,0x4AD,0xA4D,0x41A4D,0xD25,0x81AA5,0xB54,0xB6A,0x612DA,0x95B,0x49B,0x41497,0xA4B,0xA164B, 0x6A5,0x6D4,0x615B4,0xAB6,0x957,0x5092F,0x497,0x64B, 0x30D4A,0xEA5,0x80D65,0x5AC,0xAB6,0x5126D,0x92E,0xC96,0x41A95,0xD4A,0xDA5,0x20B55,0x56A,0x7155B,0x25D,0x92D,0x5192B,0xA95,0xB4A,0x416AA,0xAD5,0x90AB5,0x4BA,0xA5B, 0x60A57,0x52B,0xA93,0x40E95);
madd[0]=0;
madd[1]=31;
madd[2]=59;
madd[3]=90;
madd[4]=120;
madd[5]=151;
madd[6]=181;
madd[7]=212;
madd[8]=243;
madd[9]=273;
madd[10]=304;
madd[11]=334;
 
function GetBit(m,n){
    return (m>>n)&1;
}

function e2c(){
    TheDate= (arguments.length!=3) ? new Date() : new Date(arguments[0],arguments[1],arguments[2]);
    var total,m,n,k;
    var isEnd=false;
    var tmp=TheDate.getYear();
    if(tmp<1900){
        tmp+=1900;
    }
    total=(tmp-1921)*365+Math.floor((tmp-1921)/4)+madd[TheDate.getMonth()]+TheDate.getDate()-38;
 
    if(TheDate.getYear()%4==0&&TheDate.getMonth()>1) {
        total++;
    }
    for(m=0;;m++){
        k=(CalendarData[m]<0xfff)?11:12;
        for(n=k;n>=0;n--){
            if(total<=29+GetBit(CalendarData[m],n)){
                isEnd=true; break;
            }
            total=total-29-GetBit(CalendarData[m],n);
        }
        if(isEnd) break;
    }
    cYear=1921 + m;
    cMonth=k-n+1;
    cDay=total;
    if(k==12){
        if(cMonth==Math.floor(CalendarData[m]/0x10000)+1){
            cMonth=1-cMonth;
        }
        if(cMonth>Math.floor(CalendarData[m]/0x10000)+1){
            cMonth--;
        }
    }
}
 
function GetcDateString(){
    var tmp="";
    tmp+=tgString.charAt((cYear-4)%10);
    tmp+=dzString.charAt((cYear-4)%12);
    tmp+="(";
    tmp+=sx.charAt((cYear-4)%12);
    tmp+=")年 ";
    if(cMonth<1){
        tmp+="(闰)";
        tmp+=monString.charAt(-cMonth-1);
    }else{
        tmp+=monString.charAt(cMonth-1);
    }
    tmp+="月";
    tmp+=(cDay<11)?"初":((cDay<20)?"十":((cDay<30)?"廿":"三十"));
    if (cDay%10!=0||cDay==10){
        tmp+=numString.charAt((cDay-1)%10);
    }
    return tmp;
}
 
function GetLunarDay(solarYear,solarMonth,solarDay){
//solarYear = solarYear<1900?(1900+solarYear):solarYear;
    if(solarYear<1921 || solarYear>2020){
        return "";
    }else{
        solarMonth = (parseInt(solarMonth)>0) ? (solarMonth-1) : 11;
        e2c(solarYear,solarMonth,solarDay);
        return GetcDateString();
    }
}
function showLunarDay(date) {
    var D=date;
    var yy=D.getFullYear();
    var mm=D.getMonth()+1;
    var dd=D.getDate();
    var ww=D.getDay();
    var ss=parseInt(D.getTime() / 1000);
    if (yy<100) yy="19"+yy;

    return GetLunarDay(yy,mm,dd)
}

module.exports = {
    getLunarDay: showLunarDay
}